High-Strength Geotextiles in Ultraheavy-Load Haul Roads

The heaviest trucks serving shovel-and-truck mining operations have tripled in weight to more than 600 tonnes gross weight over the past 30 years. The design of haul roads to support these trucks is becoming ever more challenging. An additional problem is the huge demand for aggregates with which to construct these thick, wide roads. In this study of the problem, a numerical modeling investigation was performed for a 300-tonne-design axle on a granular pavement consisting of a capping layer, base, and subbase (0.5, 1.0, and 1.5 m thick, respectively). Conventional linearly elastic analyses and analyses not permitting tension were carried out. While the results of the conventional elastic analysis permitting tension had indicated that there was no reinforcing effect with these geotextiles, the results of the no-tension analysis indicated a significant reinforcement effect attributable to the inclusion of high-strength geotextiles in the cross section. The results bring into question the use of analyses permitting tension in the granular pavement materials.